What RAM and hard disk requirements are needed for running the HYSPLIT dispersion model on the PC?

The latest version of HYSPLIT uses Dynamic Array Allocation, which is a fancy term to say that the model determines how much memory it needs based on the setup of the model by the user. The finer the grid resolution, the more memory that will be needed. Harddisk space also depends on the resolution of the concentration grid as well as the size of the meteorological dataset used by the model.